Mayors cite progress against climate change

Rio de Janeiro Mayor Eduardo Paes, left, speaks with New York Mayor Michael Bloomberg on Tuesday at ﻿a meeting of the world’s mayors in Rio de Janeiro, Brazil.

On the eve of a U.N. environmental conference in Rio de Janeiro, Brazil, the world's mayors said they were taking real, measurable action to fight global warming and preserve natural resources for future generations.

The C40 grouping of mayors from 58 megacities around the globe estimated Tuesday that the nearly 5,000 measures they've already undertaken could reduce greenhouse gas emissions by more than a billion tons by 2030. That's the equivalent of the combined annual emissions of Mexico and Canada, said C40 chairman and New York City Mayor Michael Bloomberg.

"Cities have recognized the responsibility to act. We haven't waited for our national governments to go first," Bloomberg told participants at a C40 conference in Rio. It was taking place on the eve of the United Nations' three-day Conference on Sustainable Development, which happens once a decade and is expected to draw 50,000 people.

Again and again, Bloomberg stressed the contrast between the paralysis of national governments on global warming and the agility of municipal authorities, which he said were up to meeting the social and environmental challenges of the 21st century.

He said Bloomberg cities are key players in the fight against global warming because about 75 percent of global emissions take place within city limits.

Some of the projects already under way include Paris' rental bike and electric car programs, Bogota's electric taxis, Los Angeles' use of more efficient LED bulbs in its street lights, and the improved solid waste collection initiatives by New Delhi, Lagos and Mexico City.

Founded in 2005, the C40 includes megacities on six continents. Its North American member cities include Austin, Houston, Philadelphia, Seattle, Portland, San Francisco and New Orleans.